Fry the liver with some olive oil and add a cup of the medium grain rice and 2 glasses of water. Let it boil, stuff the rooster and stitch the meat tight. Continue by filling a saucepan with water and boil the rooster for 1 ½ - 2 hours approximately. Drain the juices once off the heat, and make the soup in a different saucepan adding 1 cup of the granular rice. Beat the egg white with a folk and then add the yolk, the lemon juice and continue beating. At the end, pour in the soup. Bake the rooster in the oven until golden brown.